failtest: catch mmap.

mmap can also fail on out-of-memory, and for the coming change to the
way we save and restore files we want to know about them anyway.

ccan/failtest/failtest.c

@@ -13,6 +13,7 @@
 #include <sys/wait.h>
 #include <sys/stat.h>
 #include <sys/time.h>
+#include <sys/mman.h>
 #include <signal.h>
 #include <assert.h>
 #include <ccan/time/time.h>
@@ -96,7 +97,7 @@ static unsigned int lock_num = 0;
 
 static pid_t orig_pid;
 
-static const char info_to_arg[] = "mceoxprwf";
+static const char info_to_arg[] = "mceoxprwfa";
 
 /* Dummy call used for failtest_undo wrappers. */
 static struct failtest_call unrecorded_call;
@@ -860,6 +861,30 @@ int failtest_open(const char *pathname,
 	return p->u.open.ret;
 }
 
+void *failtest_mmap(void *addr, size_t length, int prot, int flags,
+		    int fd, off_t offset, const char *file, unsigned line)
+{
+	struct failtest_call *p;
+	struct mmap_call call;
+
+	call.addr = addr;
+	call.length = length;
+	call.prot = prot;
+	call.flags = flags;
+	call.offset = offset;
+	call.fd = fd;
+
+	p = add_history(FAILTEST_MMAP, file, line, &call);
+	if (should_fail(p)) {
+		p->u.mmap.ret = MAP_FAILED;
+		p->error = ENOMEM;
+	} else {
+		p->u.mmap.ret = mmap(addr, length, prot, flags, fd, offset);
+	}
+	errno = p->error;
+	return p->u.mmap.ret;
+}
+
 static void cleanup_pipe(struct pipe_call *call)
 {
 	if (!call->closed[0])

ccan/failtest/failtest.h

@@ -47,6 +47,7 @@ enum failtest_call_type {
 	FAILTEST_READ,
 	FAILTEST_WRITE,
 	FAILTEST_FCNTL,
+	FAILTEST_MMAP,
 };
 
 struct calloc_call {
@@ -110,6 +111,16 @@ struct fcntl_call {
 	} arg;
 };
 
+struct mmap_call {
+	void *ret;
+	void *addr;
+	size_t length;
+	int prot;
+	int flags;
+	int fd;
+	off_t offset;
+};
+
 /**
  * struct failtest_call - description of a call redirected to failtest module
  * @type: the call type
@@ -151,6 +162,7 @@ struct failtest_call {
 		struct read_call read;
 		struct write_call write;
 		struct fcntl_call fcntl;
+		struct mmap_call mmap;
 	} u;
 };
 

ccan/failtest/failtest_override.h

@@ -29,6 +29,7 @@
 /* Replacement of I/O. */
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <sys/mman.h>
 #include <fcntl.h>
 #include <unistd.h>
 
@@ -62,6 +63,11 @@
 #undef fcntl
 #define fcntl(fd, ...) failtest_fcntl((fd), __FILE__, __LINE__, __VA_ARGS__)
 
+#undef mmap
+#define mmap(addr, length, prot, flags, fd, offset)			\
+	failtest_mmap((addr), (length), (prot), (flags), (fd), (offset), \
+		      __FILE__, __LINE__)
+
 /* Replacement of getpid (since failtest will fork). */
 #undef getpid
 #define getpid() failtest_getpid(__FILE__, __LINE__)

ccan/failtest/failtest_proto.h

@@ -21,6 +21,8 @@ ssize_t failtest_pread(int fd, void *buf, size_t count, off_t offset,
 		       const char *file, unsigned line);
 ssize_t failtest_pwrite(int fd, const void *buf, size_t count, off_t offset,
 			const char *file, unsigned line);
+void *failtest_mmap(void *addr, size_t length, int prot, int flags,
+		    int fd, off_t offset, const char *file, unsigned line);
 int failtest_close(int fd, const char *file, unsigned line);
 int failtest_fcntl(int fd, const char *file, unsigned line, int cmd, ...);
 pid_t failtest_getpid(const char *file, unsigned line);

ccan/failtest/failtest_undo.h

@@ -31,6 +31,10 @@
 #define write(fd, buf, count) \
 	failtest_write((fd), (buf), (count), NULL, 0)
 
+#undef mmap
+#define mmap(addr, length, prot, flags, fd, offset) \
+	failtest_mmap((addr), (length), (prot), (flags), (fd), (offset), NULL, 0)
+
 #undef close
 #define close(fd) failtest_close(fd)